Inertia type governor



y 1, 1934- F. BAUMGARTNER 1,957,311

INERTIA TYPE GOVERNOR Filed March 27. 1931 2 Sheets-Sheet 1 Hg. 1 fly. 2.

WITNESSES:

25 /5 25 INVENTOR 4% 6 W60 Baumgarznert a/ BY 7% Q MW y 1934- F. BAUMGARTNER ,957,

INERTIA TYPE GOVERNOR Filed March 27. 1931 2 Sheets-Sheet 2 WITNESSES: 22 INVENTOR w fieafiaamgarmer.

Patented May 1, 1934 UNITED STATES INERTIA TYPE GOVERNOR Fred Baumgartner, Chicago, 111., assignor to Westinghouse Electric Elevator Company, a

corporation of Illinois Application March 27,

3 Claims.

My invention relates to elevator governors and more specifically to governors of the inertia type which trip and set car safety devices to stop the cars when their rates of acceleration become excessive.

It is customary, in elevator practice, to provide an overspeed governor which is driven by a governor rope at speeds corresponding to the speed of the elevator car in the hatchway. When the speed of the car becomes excessive, for any reason, such as a defective control system or broken hoist cables, the overspeed governor trips a pair of rope-gripping jaws which grip the governor rope to set the car safety device and stop the car.

A common fault of such systems is that, upon the'occurrence of emergency conditions, the car speed must increase to a certain predetermined rate above the normal speed before the overspeed governor will trip. Therefore, if the emergency occurs as the car approaches the end of its hatchway, it will run into the. buffer at a high rate of speed before the safety device has time to operate. This defect is inherent in all elevator safety systems which are responsive onlyv to the speed of the car, because the governor is adjusted topermit the operation of the car at its full normal speed.

It is an object of my invention to provide a governor which will operate to set the safety device immediately upon the occurrence of any emergency condition which causes the car to accelerate at an excessive rate.

It is also an object of my invention to provide a governor which will be responsive to either over-speeding or over-acceleration.

A further object of my invention is to provide an overspeed inertia governor which will be of simple rigid construction, conveniently adjustable and fool-proof.

The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof,will best be understood from the follow-- ing description of specific embodiments, when read in conjunction with the accompanying drawings in which:

Figure 1 is a view, in side elevation of an elevator system designed in accordance with one form of my invention;

Fig. 2 is a view, in cross-section of one form of the governor of my invention;

Fig. 3 is a development of the cam surface of the governor shown'in Fig.2;

1931, Serial No. 525,713

Fig. 4 is an analytical diagram illustrating the principle of operation of my governor;

Fig. 5 is a sectional view of a modification of my invention embodying both speed and acceleration-responsive characteristics; and

Fig. 6 is a sectional view taken on the line VI-VI of Fig. 5.

,Referring more specifically to the drawings, the apparatus shown in Fig. 1 comprises an elevator car C suspended by a hoist cable Ca passing over a hoist sheave 11 to a counterweight CWT, in a well known manner. The hoist sheave 11 may be driven and controlled by any well known elevator system (not shown). A safety device S is carried by the car C and may be any well known safety device of a type which is set to'grip the rails and stop the car when a safety cable 12 is unreeled from a safety drum.

A governor rope 13, passing over a governor sheave 14 at the top of the hatchway and under (5 an idler sheave 15 at the bottom of the hatchway, is releasably secured to the car by a mini ball 16. The mini ball 16 is attached to the governor rope 13 and is received by a spring clip 1'7 on the car. The free end of the safety cable 12 is secured to the governor rope 13 by the mini ball 16 which, therefore, serves a dual purpose.

A governor 21 is associated with the governor sheave 14 and is driven thereby at speeds corresponding to the speed of the car in the hatch- Way The governor comprises a vertical shaft 22 which may be driven from the sheave 14 through a bevel gear or any other suitable driving connection. The governor, associated with the upper end of the vertical shaft, may be only an inertia device which is responsive to acceleration, as shown in Fig. 2, or it may be a device Which is responsive to both speed and acceleration, as shown in Fig. 5. The governor represented in Fig. 1 corresponds to the device shown in Fig. 5 which is responsive to both speed and acceleration, but it is to be understood that either device may be utilized, as desired.

The upper end of the vertical shaft 22 may be turned to provide a shoulder 23 (Fig. 2) spaced below the upper end thereof. A cam collar 24 is concentrically disposed on the shaft 22 and rests in abutting engagement upon the shoulder 23. A pin or any suitable key may be provided for securing the cam collar 24 to the shaft 22. The cam collar 24 presents upwardly exposed cam surfaces comprising diametrically op posed depressions 25 and peaks 26.

The complete development of the cam surface, as shown in Fig. 3, comprises two depressions 25 and two peaks 26 which are so arranged that the peaks have steeply sloping sides in one direction and gently sloping sides in the other direction, and any pair of diametricaly opposed points will have the same elevations.

A roller housing 31, having a massive rim 32, is concentrically disposed on the shaft 22 about the cam collar 24 and carries a pair of rollers 33 which are journalled on the inner ends of diametrically opposed pins 34 extending from the walls of the housing toward the vertical shaft. The rollers rest upon the cam surface of the collar 24 and thereby support the roller housing 31 on the shaft 22. The cam surfaces are beveled outwardly, and the cooperating rollers 33 are correspondingly beveled, as shown in Fig. 2, in order that their reactions may be equalized, and the housing 31 may be supported in a position of accurate alignment.

The roller chamber is closed at the bottom by a bearing 36 and at the top by a cover plate 37 secured thereto in any suitable manner. This arrangement prevents the entrance of dirt or foreign matter, which might interfere with the operation of the rollers, and keeps them well lubricated. Above the cover plate, a compression spring 38 is concentrically disposed on the upper end of the vertical shaft 22, which is threaded to receive a nut 39 for adjusting the compression thereof. By turning the nut 39 to vary the tension of the spring 38 on the cover plate 37, the operating characteristics of the governor may I be so modified as to respond to a higher or to a lower degree of acceleration, as desired.

During normal operation, the weight of the massive roller housing 31 and the tension of the spring 38 tend to hold the rollers 33 down in the depressions 25 of the cam surface, whereby the housing is constrained to rotate synchronously with the shaft 22. However, when the elevator car'accelerates at an excessive rate, the massive roller housing, because of its high moment of inertia, offers considerable resistance to the sudden change of motion. This resistance manifests itself as a horizontal force acting on the roller, and, referring to Fig. 1, its magnitude can be shown to be (ifonly' one roller is used), where I is the inertia moment of the housing in weight units, U the angular aceleration of the shaft, g gravity in feet, and r is the radius, as shown in Fig. 2, in feet. In order that the roller may climb an incline of a degrees, the force F must be somewhat greater than Q tan (a-i-b) where Q is the vertical load on the roller, a is the angle of the incline and b is the rolling friction angle. The resistance acts as a horizontal force F, tending to pull the rollers 33 up the gently inclined slopes and over the peaks 26 of the cam surfaces.

As the rollers 33 ascend the sloping surfaces and pass over the peaks, the roller housing 31 is lifted. In order that the safety S on the car shall be actuated when the housing is lifted, a collar 41 is provided on an external portion of the housing, and any suitable actuator means may be associated therewith for tripping the conventional rope-gripping jaws to rope-gripping position.

As shown in Fig. l, the actuator mechanism may comprise a lever 42, one end of which is associated with a fixed pivot and the free end of which is connected to the rope-gripping jaws 43 by a link or flexible connector 44. The ropegripping jaws 43 may be of any well known construction in common use on overspeed governors. However, since the embodiment of my invention shown in Fig.2 is not responsive to overspeeding, it is intended to be used on, or in conjunction with, the usual overspeed governor. The rope-gripping jaws may, therefore, be the jaws which are a part of the usual overspeed governor.

In the event that something should suddenly obstruct or stop the rotation of the vertical shaft 22 when it is operating at a high rate of speed, severe stresses would be set up in various parts of the governor if the massive roller housing and inertia disc must be stopped immediately. It is to avoid this condition that the steep incline is provided on the back of each peak 26. If this portion of the cam surface were vertical, it would act as a positive stop member to the rollers and would retard the massive inertia disc suddenly, thereby straining various parts of the governor. However, as the back surfaces are inclined, the rollers will climb over the peaks, and the massive rotating parts will come to rest gradually.

The purpose of the lesser slope in front of each peak is to make the governor sensitive to any abnormal acceleration in one direction only. The cam surfaces may be designed to have any suitable angular inclinations in accordance with the operating characteristics desired. If desired, the cam surfaces may be made to slope gently on both sides of the peak.

The embodiment of my invention illustrated in Fig. 5 is designed to respond and trip the rope gripping jaws 43, either when the car overspeeds or when it over-accelerates and it replaces the usual overspeed governor. In this form of my invention, a cam collar 51 is mounted on the vertical shaft 22 in abutting relation to the shoulder 23, in a manner very similar to that of the previous device except that the upturned cam surfaces present only a single depression 25 and a single peak 26. The inclined surfaces may 120 slope gently on one side of the peak and steeply on the other, as set forth with reference to the first embodiment.

A roller housing 52 is concentrically disposed on the shaft 22 about the cam collar 51. A single roller 53 is journalled on the inner end of an inwardly directed shaft 54 which is threaded through the wall of the housing and extends toward the vertical shaft, as more clearly shown in Fig. 6. The roller 53 rests in the depression 25 on the cam surface of the collar 51 and thereby supports the roller housing 52 on the shaft '22. A cover plate 55 closes the upper portion of the roller housing and may be secured in position by screws 56 or other suitable fastening means.

A laterally-extending inertia disc 57 is carried by the housing 52 to increase its moment of inertia. A compression spring 58, is concentrically disposed on the upper end of the vertical shaft 22 which is threaded to receive a nut. 59 for adjusting the tension of the spring. By turning the nut 59, the biasing force exerted by the spring 58 on the cover plate 55 may be varied to thereby vary the operating characteristics of the inertia governor, as desired.

The fiyballs 61 of the speed governor are suspended from the roller housing 52 or the inertia disc 57 by pivoted lever arms 62, whereby the weight of the ilyballs increases the inertia of the housing and disc.

Both systems act upon a collar 63 which is slidably mounted in concentric relation on the portion of the vertical shaft 22 below the roller housing. The collar 63 is supported by link members 64 pivotally attached to intermediate portions of the ilyball lever arms 62. An externally threaded sleeve 65 extends downwardly from the roller housing 52 in concentric relation to the vertical shaft 22 and carries an adjustable nut 66. A biasing spring 67 reacts between the adjustable nut 66 and the lower collar 63 and thereby tends to thrust the collar to its lowermost position and retract the fiyballs 61.

When the car is in motion, the vertical shaft 22 rotates and, as the centrifugal force, acting on the flyballs 61, overcomes the tension of the spring 67, the balls move outwardly and, through links 64, pull the collar 63 up against the spring 6'7. As the collar is lifted, it tilts the actuator lever 42, and, if a predetermined degree of overspeed is attained, the rope-gripping jaws 43 are tripped, and the safety device S is applied in a well known manner. By turning the springpressing nut 66 on the sleeve 65, the tension of the spring 6'7 and the speed characteristics of the governor may be adjusted as desired.

If the car is stationary or is moving at a normal rate of speed and, for some reason, such as a broken hoist cable or a defective control system, it begins to accelerate at an excessive rate, the high moment of inertia of the roller housing and all the parts that rotate therewith will cause the roller 53 to climb the inclined surface and pass over the peak of the cam 51. As the roller 53 ascends the inclined surface, it lifts the housing 52 which, in turn, lifts the collar 63 through the fiyoall arm and link members. The resulting elevation of the collar 63 operates the actuator mechanism to trip the rope-gripping jaws 43 and apply the car-safety device in the usual manner.

It will be seen that I have provided a simple and rugged inertia governor which is responsive to acceleration alone or to both acceleration and speed, and which is enclosed, compact and readily adjustable.

Although I have shown and described certain specific embodiments of my invention, I am fully aware that many modifications thereof are possible. My invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims.

I claim as my invention:

1. In a safety governor for controlling the operation of a moving body, a vertical shaft for operation in accordance with the speed of said body, a cam collar concentrically and fixedly secured on said shaft and presenting upwardly exposed cam surfaces having a depression, a housing concentrically disposed about said shaft and cam collar, roller means for supporting the housing, said roller means projecting inwardly from said housing into cooperative relation with said cam surfaces, and means for biasing the housing downwardly, whereby the roller means rests in the depression in the cam surfaces and rotates therewith during normal operation of the shaft but leaves the depression and ascends the cam surfaces to raise the roller supported housing against said biasing means upon abnormal operation of the shaft.

2. In a safety governor for controlling the speed and acceleration of a moving body, a vertical shaft for operation in accordance with the speed and acceleration of said body, a cam collar concentrically secured on said shaft and presenting upwardly exposed cam surfaces having diametrically opposed depressions, a roller housing concentrically disposed about said cams and shaft collar, diametrically opposed rollers projecting inwardly from said housing into cooperative relation with said cam surfaces for supporting the housing on the shaft, and means for biasing the housing downwardly whereby the rollers rest in the depressions and rotate the housing therewith during normal operation of the shaft but leave the depressions and ascend the cam surfaces to raise the roller supported housing against said biasing means upon abnormal operation of the shaft.

3. In a safety governor for controlling the acceleration and speed of a moving body, a vertical shaft for operation in accordance with the speed of said body, a cam collar concentrically disposed and keyed to said shaft, said collar presenting upwardly exposed cam surfaces with diametrically opposed depressions having steep sloping sides in one direction of rotation and gentle sloping sides in the other direction of rotation, a roller housing concentrically disposed about said shaft and cam collar, diametrically opposed rollers projecting inwardly from said housing into cooperative relation with said cam surfaces to support the housing, and means for biasing the housing downwardly, whereby the rollers rest in the depressions in the cam surfaces and rotate the housing therewith during normal operation of the shaft but leave the depressions and ascend the cam surfaces to raise the roller supported housing against said biasing means upon abnormal operation of the shaft.

FRED BAUMGARTNER. 

